Pap smears have been used regularly for diagnosing cervical cancer. Pap smear tests have an approximately 70% sensitivity (true positive/total number of actual abnormal cases. Generally when using a Pap smear for diagnosing cervical cancer, internal tissue areas in the cervix are scraped and analyzed by a microscope to check for abnormal tissues.
Following an abnormal Pap smear, a patient is recommended for a more in depth examination by a gynecologist specializing in cancer, including cancer of the female genital track. Colposcopy (i.e., observation of the cervix) is typically performed on the patient. During colposcopy, a colposcope (a magnifying microscope) is used to attempt to identify suspect lesions. A colposcope image of the cervix is reproduced at a remote distance from the patient. Subsequent to colposcopy, biopsy of suspected lesions is commonly performed for histology follow up. When a biopsy is performed, several tissue samples are cut-out and sent to a cytology laboratory for further analysis. While there are various classifications for degree of cell abnormality, an abnormal lesion can include atypical cells, virus infected cells such as human papilloma, pre malignant cells, and malignant cancer cells.
There are several problems with using the Pap smear first followed by either or both the biopsy and/or the colposcopy. Patient compliance is a major problem to having a biopsy performed. Patients have been known to procrastinate and delay these follow-up procedures because of fear of having a biopsy. This time delay hurts the chance of recovery, since cancer is best treated in its earliest stage. Problems are further compounded because every time abnormal cells are detected during a Pap smear, there has to be another colposcopy and another biopsy. Repeating Pap smears followed each time by colposcopy and biopsy increases the odds of not obtaining patient compliance. Additional problems exist with pregnant patients, because biopsy is not recommended during pregnancy due to the increased risk of bleeding.
Inventions have been proposed for overcoming these problems, but still fail to adequately cover all of these problems with a single procedure. See for example U.S. Pat. No. 5,179,937 to Lee; U.S. Pat. No. 5,321,501 to Swanson et al.; 5,451,785 to Faris; U.S. Pat. No. 5,458,595 to Tadir et al.; U.S. Pat. No. 5,465,147 to Swanson; U.S. Pat. No. 5,467,767 to Alfano et al.; U.S. Pat. No. 5,491,524 to Hellmuth et al.; U.S. Pat. No. 5,496,305 to Kittrell et al.; U.S. Pat. No. 5,507,287 to Palcic et al.; U.S. Pat. No. 5,537,162 to Heilmuth et al.; U.S. Pat. No. 5,558,669 to Reynard; U.S. Pat. No. 5,573,531 to Gregory; and U.S. Pat. No. 5,591,160 to Reynard. U.S. Pat. Nos. 5,321,501 and 5,451,785 to Swanson are the closest prior art devices that mention it may be desirable to scan tissue inside tubular structures such as genital tracts. However, these patents do not conduct imaging and spectroscopy simultaneously.